Spatial geometry of stem cell proliferation in the adult hippocampus

The modes of stem cell divisions (e.g., symmetric vs. asymmetric) can have a profound impact on the number of progeny and tissue growth, repair, and function. This is particularly relevant for adult neural stem cells, since stem cell-derived neurons affect cognitive and mental states, resistance to stress and disease, and response to therapies. Here we show that although dividing stem cells in the adult hippocampus display a certain bias towards paired distribution (which could imply the prevalence of symmetric divisions), this bias already exists in the distribution of the general population of stem cells and may be responsible for the perceived occurrence of symmetric stem cell divisions. Remarkably, the bias in the distribution of stem cells decreases with age. Our results argue that the preexisting bias in stem cell distribution may affect current assumptions regarding stem cell division and fate as well as conjectures on the prospects of brain repair and rejuvenation

Results of a study of genetic factors predisposing to the development of psoriasis among the population of the Russian Federation

Goal. To assess the incidence of genes predisposing to the development of psoriasis based on selected molecular and genetic study methods among the Russian population. Materials and methods. By using allele specific hybridization methods in the form of real-time PCR and RFLP assay (Restriction Fragment Length Polymorphism), single-nucleotide polymorphisms of fragments of 13 genes associated with predisposition to the development of psoriasis were studied in whole blood samples obtained from 45 psoriatic patients: rs4649203 (gene IL-28RA), rs11209026 (gene IL-23R), rs610604 (gene TNFAIP3), rs514315 (gene SERPINB8), rs9304742 (gene ZNF816A), rs17728338 (gene TNIP1), rs13190932 (gene TRAF3IP2), rs2235617 (gene ZNF313), rs27524 (gene ERAP1), rs702873 (gene REL), rs3213094 (gene IL-12B), rs12720356 (gene TYK2), and rs8016947 (gene NFKBI). Results. A set of data on the genotype structure and incidence in respective loci of 13 genes associated with predisposition to develop psoriasis was obtained for the first time based on a Russian sample of patients. At this stage of the study, we failed to reveal any reliable differences concerning the incidence of individual genotypes between psoriatic patients and healthy people because of the small size of the sample. Gene TYK2 (rs1272035) served as an exclusion. The homozygous T/T genotype was revealed more often (p &lt; 0.01) in psoriatic patients (95.6%) vs. healthy people (77.8%), which makes it possible to consider the carriers of this genotype as people predisposed to the development of psoriasis.</jats:p

Association of polymorphisms in TNFAIP3 and TNIPI genes with predisposition to the development of psoriasis in the Russian population

Goal. To study polymorphisms in TNFAIP3 (rs610604) and TNIPI (rs17728338) genes in a sample of psoriasis patients and healthy volunteers from the Russian Federation. Materials and methods. By using allele specific hybridization methods in the form of real-time PCR and RFLP assay (Restriction Fragment Length Polymorphism), single-nucleotide polymorphisms of fragments of the following genes associated with predisposition to the development of psoriasis were studied in whole blood samples taken from psoriasis patients (n = 286) and healthy volunteers (n = 89): TNFAIP3 (rs610604) and TNIPI (rs17728338). Results. Psoriasis patients had a reliable increase in the frequency of the A/C heterozygous genotype of rs610604 polymorphism of the TNFAIP3 gene and A allele of rs17728338 polymorphism of the TNIP1 gene (A/G and A/A genotypes), which makes it possible to treat carriers of these genotypes as people with predisposition to the development of psoriasis, and to treat A/C genotypes of rs610604 polymorphism and A/G and A/A genotypes of rs17728338 polymorphism as predictors of the development of psoriasis in the Russian population. Conclusion. these data broaden the perception of genetic factors associated with the development of psoriasis in persons from the Russian population.</jats:p

Langerhans cell histiocytosis (histiocytosis x): a case study

The authors provide a case study of Langerhans cell histiocytosis (histiocytosis X) in a two-year-old girl. They describe major stages of the etiology and pathogenesis as well as clinical forms of the disease. Langerhans cell histiocytosis (histiocytosis X) is a rare disease characterized by lesions of the skin and internal organs.</jats:p

Calorie restriction alleviates the age-related decrease in neural progenitor cell division in the aging brain

Production of new neurons from stem cells is important for cognitive function, and the reduction of neurogenesis in the aging brain may contribute to the accumulation of age-related cognitive deficits. Restriction of calorie intake and prolonged treatment with rapamycin have been shown to extend the lifespan of animals and delay the onset of the age-related decline in tissue and organ function. Using a reporter line in which neural stem and progenitor cells are marked by the expression of green fluorescent protein (GFP), we examined the effect of prolonged exposure to calorie restriction (CR) or rapamycin on hippocampal neural stem and progenitor cell proliferation in aging mice. We showed that CR increased the number of dividing cells in the dentate gyrus of female mice. The majority of these cells corresponded to nestin-GFP-expressing neural stem or progenitor cells; however, this increased proliferative activity of stem and progenitor cells did not result in a significant increase in the number of doublecortin-positive newborn neurons. Our results suggest that restricted calorie intake may increase the number of divisions that neural stem and progenitor cells undergo in the aging brain of females